1. Field of the Invention
The present invention relates to data transmission systems for use in a disaster-prevention or crime-prevention system, robot control or the like.
2. Prior Art
A data transmission system such as a remote sensing system consists of a controller, terminals installed at any desired places, and transmission lines for connecting the terminals with the controller, in which the system collects and processes data obtained by each terminal at the controller and, in turn, transmits data from the controller to each terminal. In such a remote sensing system, in general, data has been transmitted between the controller side and the sensor terminal side by the method of multiplexing signals. That is, frequency division or time division has been used to realize the multiplex transmission of signals.
However, the data transmission system using multiplex transmission necessitates providing a transmission control section to both the controller side and each sensor terminal side, resulting in very high cost.